Related Experiment Video
Updated: Jun 27, 2026
Three-dimensional Quantification of Intestinal Mucus Using Whole-mount Tissue Imaging
Published on: September 12, 2025
Mucin dynamics in intestinal bacterial infection
Sara K Lindén1, Timothy H J Florin, Michael A McGuckin
1Mucosal Diseases Program, Mater Medical Research Institute, Mater Health Services, South Brisbane, Queensland, Australia.
Background:
Bacterial gastroenteritis causes morbidity and mortality in humans worldwide. Murine Citrobacter rodentium infection is a model for gastroenteritis caused by the human pathogens enteropathogenic Escherichia coli and enterohaemorrhagic E. coli. Mucin glycoproteins are the main component of the first barrier that bacteria encounter in the intestinal tract.
Methodology/Principal Findings:
Using Immunohistochemistry, we investigated intestinal expression of mucins (Alcian blue/PAS, Muc1, Muc2, Muc4, Muc5AC, Muc13 and Muc3/17) in healthy and C. rodentium infected mice. The majority of the C. rodentium infected mice developed systemic infection and colitis in the mid and distal colon by day 12. C. rodentium bound to the major secreted mucin, Muc2, in vitro, and high numbers of bacteria were found in secreted MUC2 in infected animals in vivo, indicating that mucins may limit bacterial access to the epithelial surface. In the small intestine, caecum and proximal colon, the mucin expression was similar in infected and non-infected animals. In the distal colonic epithelium, all secreted and cell surface mucins decreased with the exception of the Muc1 cell surface mucin which increased after infection (p<0.05). Similarly, during human infection Salmonella St Paul, Campylobacter jejuni and Clostridium difficile induced MUC1 in the colon.
Conclusion:
Major changes in both the cell-surface and secreted mucins occur in response to intestinal infection.
Insights
Intestinal mucins, like Muc2, limit bacterial access. During infection, cell-surface mucin Muc1 increases, while others decrease, indicating major changes in the gut barrier response.
Area of Science:
- Microbiology
- Immunology
- Gastroenterology
Background:
- Bacterial gastroenteritis is a significant global health issue.
- Citrobacter rodentium infection in mice serves as a model for human enteropathogenic E. coli.
- Mucin glycoproteins form the primary physical barrier in the intestinal tract.
Purpose of the Study:
- To investigate the expression of various mucins in the mouse intestine during Citrobacter rodentium infection.
- To understand the role of mucins in host defense against bacterial gastroenteritis.
Main Methods:
- Immunohistochemistry was used to analyze mucin expression (Alcian blue/PAS, Muc1, Muc2, Muc4, Muc5AC, Muc13, Muc3/17) in healthy and infected mice.
- In vitro binding assays were performed to assess the interaction between C. rodentium and Muc2.
- Bacterial load and localization were examined in vivo.
Main Results:
- C. rodentium infection led to colitis and systemic infection in mice by day 12.
- C. rodentium bound to Muc2 in vitro, and bacteria were found within secreted Muc2 in vivo, suggesting mucins limit epithelial access.
- While most mucins remained unchanged in the small intestine, cecum, and proximal colon, distal colonic epithelium showed decreased secreted and cell-surface mucins, except for an increase in Muc1.
- Human infections (Salmonella St Paul, Campylobacter jejuni, Clostridium difficile) also induced MUC1 in the colon.
Conclusions:
- Intestinal infection triggers significant alterations in both cell-surface and secreted mucins.
- Mucins play a crucial role in the host's innate immune response to bacterial gastroenteritis.
Related Concept Videos
01:20Inflammatory Bowel Disease II: Ulcerative Colitis
01:25Inflammatory Bowel Disease III: Crohn's Disease
01:27Microbiota of the Stomach and Small Intestine
01:18Dysbiosis of the Gut Microbiota
01:25Mucosal Barrier of the Stomach
Within parietal cells, carbonic acid is first formed through the reaction of water and carbon dioxide. The dissociation of carbonic acid releases bicarbonate and hydrogen ions. The bicarbonate...
01:24Pathophysiology of Peptic Ulcer Disease: Mucosal Defense Factors